Option C: ∠2 and ∠8
Option E: ∠3 and ∠5
Solution:
Two parallel lines cut by a transversal.
Option A: ∠5 and ∠4
∠4 is not interior of parallel lines.
Hence it is not true.
Option B: ∠6 and ∠5
∠6 is not interior of parallel lines.
Hence it is not true.
Option C: ∠2 and ∠8
∠2 and ∠8 lies in the interior of the parallel lines.
∠2 and ∠8 lies in alternate of the transversal line.
Therefore, ∠2 and ∠8 are alternate interior angles.
Hence it is true.
Option D: ∠8 and ∠1
∠1 is not interior of parallel lines.
Hence it is not true.
Option E: ∠3 and ∠5
∠3 and ∠5 lies in the interior of the parallel lines.
∠3 and ∠5 lies in alternate of the transversal line.
Therefore, ∠3 and ∠5 are alternate interior angles.
Hence it is true.
Therefore ∠2 and ∠8, ∠3 and ∠5 are alternate interior angles.
